1. Field of the Invention
The present invention relates to an apparatus for inspecting a collimator.
2. Description of the Related Art
A collimator refers to a device for optical communication, which transforms light, which enters by a light source into a parallel ray. The collimator is usually used, as a component, in a variety of equipment including optical communication equipment, semiconductor equipment, etc.
A typical collimator, as shown in FIG. 1, comprises a pigtail 12 and a GRIN (gradient index) lens 14, both being arranged on a mutual coaxial line, a glass tube 15 receiving and supporting the pigtail 12 and the GRIN lens 14, and a tubular metal sleeve 16 protecting the glass tube 15 on the outside thereof.
In the pigtail 12 formed of glass is provided a pair of fibers 13a and 13b forming an incoming channel of a predetermined light in one end of the pigtail 12, through which the light enters. In the other end of the pigtail 12 is formed a predetermined sloping side 12a. 
One end of the GRIN lens 14 disposed coaxially relative to the pigtail 12 is formed as a sloping side 14a corresponding to the predetermined sloping side 12a of the pigtail 12. The sloping side 12a of the pigtail 12 and the sloping side 14a of the GRIN lens 14 are slopingly disposed oppositely to each other.
To manufacture a collimator 10 with this configuration, a GRIN lens 14 is fixedly inserted into a glass tube 15. One end of the GRIN lens 14, on which a sloping side 14a is formed, is inserted into the glass tube 15 and the other end thereof is disposed so as to be exposed to the outside of the glass tube 15 with a predetermined distance of the exposed GRIN lens 14.
If the GRIN lens 14 is supportedly received in one side of the glass tube 15, a pigtail 12 is inserted from the other side thereof. One end of the pigtail 12, on which the predetermined sloping side 12a is formed, is received within the glass tube 15 and then the pigtail 12 is slopingly displaced so as to be opposite to the sloping side 14a of the GRIN lens 14 already having been supportedly inserted within the glass tube 15.
At this time, the predetermined sloping side 12a of the pigtail 12 is slopingly disposed relative to the sloping side 14a of the GRIN lens 12 through an aligning process so as to comply with predetermined conditions for optical properties. Thereafter, if the collimator 10 is in compliance with some predetermined conditions, the pigtail 12 is fixed within the glass tube 15.
If the GRIN lens 14 and the pigtail 12 are supportedly received within the glass tube 15, the glass tube 15 is inserted into the tubular metal sleeve 16. Then, the glass tube 15 and the metal tubular sleeve 16 are coated with epoxy resins 17, and the glass tube 15 and the tubular metal sleeve 16 are fixedly combined with each other. With these processes, manufacture of the conventional collimator 10 is completed.
However, in a conventional art, no separate apparatus for inspecting the collimator 10 manufactured through the above-described processes is available, thereby causing the product reliability of the conventional collimator to decrease accordingly.
The present invention is an apparatus for inspecting properties of a collimator by inspecting the collimator in part, thereby allowing the product reliability to increase.
Additional objects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.
This and other objects of the present invention may be achieved by providing an apparatus for inspecting a collimator including a pigtail formed with first and second fibers, a GRIN lens disposed coaxially relative to the pigtail, and a glass tube supporting the pigtail and the GRIN lens in a single unit, to inspect optical properties of the collimator, the apparatus comprising an inspection table; a gripping part provided on the inspection table, gripping the collimator subject to inspection; a light supplying part transmitting a predetermined optical signal to the first fiber; a light receiving part connected to the second fiber, receiving an optical signal returned from the second fiber, after entering the first fiber; a measuring part calculating a value of the predetermined optical signal which entered the first fiber and a value of the optical signal returned from the second fiber; and an image displaying part displaying a value obtained from the measuring part.
The measuring part may deduct the value of the optical signal returned from the second fiber from the value of the predetermined optical signal which entered the first fiber, to obtain a value of return loss.
The apparatus may further comprise a total reflection mirror positioned coaxially relative to the collimator at a predetermined distance from the collimator and totally reflecting the predetermined optical signal which entered the first fiber.
The measuring part may deduct a value of the optical signal returned from the second fiber after being totally reflected by the total reflection mirror from the value of the predetermined optical signal which entered the first fiber, to thereby obtain a value of reflected insertion loss.